1.37 Figure P1.37 shows the circuit of an N-bit digital-to-analog converter (DAC). Each of the N bits of the digital word to be converted controls one of the switches. When the bit is 0, the switch is in the position labeled 0; when the bit is 1, the switch is in the position labeled 1. The analog output is the current iO.Vref is a constant reference voltage. (a) Show that i O = V ref R 2b11 + 2b22 + ···+ 2bNN (b) Which bit is the LSB? Which is the MSB? (c) ForVref = 10 V,R = 10 k, andN = 8, find the maximum value of i O obtained. What is the change in iO resulting from the LSB changing from 0 to 1?